Q: How is it best to grow my Dahlias?
For dramatic spreads of colour in summer and autumn dahlias are hard to beat. These wonderful flowers originated in the mountain ranges of Mexico, Guatemala and Columbia, before becoming popular throughout the world.
Dahlias start to flower from around Christmas to early January, so you can plant them in October or November. It’s about eight weeks from planting to flowering. Dahlias last about a week inside as a cut flower and make a lovely display. The most important tip to remember when planting the tubers is that you don't water them until they grow up about 15 centimetres high, unless the soil is really dry, because they can rot before they begin to grow.
Dahlias flower through to the end of April, first week of May, then you should start to cut them back to about half their height, just to tidy up the garden. By the time you do that, it's then time when their leaves change colour to cut them off at ground level. They can be left in the ground for a number of years, but for best results it’s a good idea to lift and divide the tubers every couple of years.
If your soil is well drained you can leave the dahlias in and dig them up early October and put them back. But if your soil gets wet in the wintertime, they'll rot, so they’ll need to be lifted. If tubers are lifted, they need to be covered with dirt or sawdust because if tubers are left uncovered they can dry out completely.
Dahlias provide a great display in the garden and they repay fully any care you give them, with their wonderful varied blooms of the most amazing colours.